Most likely broke a lot of built up carbon from valves and combustion chamber via thermal shock to the carbon deposits. Used to do this a lot at the Ford dealer. Can be done couple of ways. We used to put it in the engine via a vacuum port. The catch is is, if it goes in too fast you can lock up the engine or bend valves...seen it happen to on several 4.0 Explorers. Usually the Sea Foam can was emptied via the brake booster port and that would let a large volume in at one time but beware... I preferred to use a smaller vacuum port. We used to inject it into the engine, then shut it off and let it sit for 15 minutes. When it restarted it looked like a mosquito fogger. Engines ran smoother and more responsive. Be very careful!